The wind project in Searsburg, a southern Vermont town of 85 people, began operation in 1997 and consists of 11 towers with a total rated capacity of 6 MW. It replaced a forested ridge top. Tillinghast examined annual reports of Green Mountain Power (GMP), the utility that owns the project (it was built by the multinational Enxco), and evaluations for the federal government by the Electric Power Research Institute (EPRI).
[Click for PDF files of GMP's annual reports: 2002 (540 KB), 2001 (600 KB), 2000 (840 KB). Click for EPRI's large PDF reports: 3rd year (1.7 MB), 2nd year (4.3 MB), 1st year (8.1 MB).
For 2002, GMP reported the plant's output as 1.2 MW in the winter and only 0.5 MW in the summer (when demand is higher). Its average annual output has consistently been less than 25% of its rated capacity and has decreased every year.
During the three years evaluated by EPRI (July 1997 through June 2000), Searsburg generated electricity, even a trickle, little more than 60% of the time. Besides the intermittency of wind, Vermont's notorious weather ("if you don't like it, just wait a minute") took its toll. Tillinghast quotes the person responsible for maintaining Searsburg: "Lightning is the big monster up here on the mountain." Lightning damage was responsible for 24% of all downtime during the three years of EPRI's study. In May 1998 one storm damaged eight turbines. In January 2000, a damaged turbine couldn't be fixed until April because a crane couldn't get up the mountain in the winter.
Wind also caused downtime, with the number of faults increasing with wind speed. Electricity output was found to decrease as wind speed increased.
On average, each of Searsburg's 11 turbines was down an average of 83 hours every month (more than 11% of the time). GMP reported a maintenance cost four times the industry norm in 2002.
Proponents of the Searsburg project said in 1996 that it would provide 0.5% of Vermont's electricity. In 2002 and 2001, it represented 0.5% of GMP's energy source, which provides about a third of the state's electricity. Its net production was 11,459 MW-h in 2002, 12,135 in 2001, and 12,246 in 2000. EPRI reported that an average of 3.3% of the power generated was lost in transmission to the substation. (The Royal Academy of Engineers in the U.K. assumes 12.5% loss will occur.) It is not recorded how much electricity the turbines themselves use, nor do their meters run "backwards" to otherwise reflect net output.
Developers of a wind project in northeast Vermont's East Haven applied in November 2003 to build 4 "demonstration" towers whose 6 MW of rated capacity (the same as Searsburg) they claim will provide the power used by 3,000 homes!)
The residents of Searsburg were generally supportive of the project as it was presented to them, and many of them still say it's a good thing. The site is not prominent, limiting its visual impact. GMP and Enxco now want to enlarge the plant. As John Zimmerman, Enxco's eastern regional director, is quoted in a March 3, 2003, Boston Globe article, "Wind has become a serious way to make money." They want to add 22 (or more) new 1.5-MW towers that are 1 2/3 times taller than the current ones (requiring lights day and night and much noisier). The larger project will spread to another mountain in another town. Reportedly most residents of both towns oppose the expansion. According to GMP, it may create one more full-time job.
Finally, Tillinghast addresses the challenge of wind advocates: "What is the alternative?" [It's a bogus challenge, of course, because wind power has no impact on the use of other energy sources --he describes the example of the Dallas-based Kimberly-Clark company cutting its energy use by 11.7% since 2000. It would require industrializing 50 mountain tops with wind plants to produce the energy saved by this one company. Vermont itself, through its office of energy efficiency, reduced electricity consumption in 2002. STillinghast concludes, "It's time for our leaders to enforce strict pollution controls and help businesses and communities conserve energy, instead of subsidizing an unproductive technology that will forever scar our wilderness."